1. Field of the Invention
This invention relates generally to the placement of granular materials and more specifically, to an Improved Apparatus and Method for Moving and Placing Granulate.
2. Description of Related Art
Sand, gravel and rock are used in a variety of applications for the construction industry. From aggregate base for concrete slabs, to back fill for retaining walls, granular materials, or granulates, are probably the most widely used substance, outside of concrete, in the construction industry. What has been a common problem has been moving the granulate from place to place when a dump truck and/or cranes and mechanical shovels do not have easy access. Over time, many attempts have been made at solving this problem. FIG. 1 depicts one attempt. FIG. 1 depicts a prior art method for constructing and maintaining a golf course. FIG. 1 shows how a patented method known as xe2x80x9cGolf-Course Construction and Maintenance Methods,xe2x80x9d of the Guettler, et al, U.S. Pat. No. 5,147,156. The Guettler method involves the movement of sand or gravel from place to place on a golf course. In the example shown, sand in a sand pile 10 is transferred to a conveyor 12, which transports the sand into a pneumatic pumping device 14. The pneumatic pumping device 14 receives pneumatic air through a supply hose 16 from a compressor 18 that presumably is trailered to the appropriate location. The Guettler method includes pressurizing the sand in the pneumatic pumping device 14, discharging it through the hose 20, and out the discharge nozzle 22. In this manner, the sand pile 10, or other sand deposit, can be moved from place to place, such as into a new sand trap, very quickly and easily and without the need of wheelbarrows or dump trucks running back and forth across the golf course.
Although the Guettler system is very effective for a golf course, it is not suitable for a wide variety of construction applications in a traditional construction environment. Since the Guettler method does not include the use of a single unitary vehicle, it is necessary to drag the compressor 18 and the pneumatic pumping device 14 by truck or other tow device to the location for its use. As such, there is a potential for damage or loss of components and further the simple additional difficulties involved with the on-site erection and dismantling of the various components to be used. Furthermore, there is no indication that the Guettler unit permits the regulation of pressure. As it will be discussed later in the present disclosure, there are several applications where high discharge pressure of the granulate will prohibit the apparatus""s use in certain applications. What is needed therefore, is a unitary vehicle that can be driven over the road, that can further move sand, gravel or rock, or other granulate, and that further permits the regulation of inlet air pressure to very low levels for specific applications.
Another application, namely the construction of concrete flatwork (slabs on grade and the like) typically require a 2- to 6-inch layer of sand, gravel or other granular material underneath a concrete slab. In these applications, a vapor barrier is often required in order to provide moisture protection. The material of choice for vapor barriers is typically of a size and material that is job-site-specific, and therefore delivered directly from the vendor to a location adjacent to the flatwork in progress. Since the vapor barrier and subsequent granulate installation are the final steps preceding the actual concrete pouring, they are not completed until all other mechanical, electrical lines and footing reinforcement bars have been installed. As such, heavy equipment cannot be driven over the pad (and lines and bars) because the lines and bars (and vapor barrier) would be disturbed. Because of this restriction, the granulate has heretofore been applied manually with wheelbarrows and shovels.
Furthermore, the process of concrete flatwork usually involves the installation of a perimeter forms for the slab (i.e. within which the concrete would be poured). These perimeter forms also interfere with the use of heavy equipment to load the granulate into the pad. What is needed is a device and method that permits the transfer of granulate into a concrete flatwork pad without disturbing the mechanical and electrical lines, the reinforcing bars, the vapor barrier or the perimeter forms.
FIG. 2 describes another attempt at solving the problem described above. FIG. 2 is another prior art method of moving and placing granular materials. FIG. 2 is a depiction of the Lightle xe2x80x9cMethod of Moving and Placing Granular Materials.xe2x80x9d U.S. Pat. No. 5,795,108. The Lightle method involves a truck 24, upon which is mounted a bed 26, within which granular material 28 is placed. The system also includes a separate air compressor 25 for supplying compressed air through the hose 27 to the truck 24. In operation, the granular material 28 exits the back of the bed 26, via the conveyor 30, where it will drop into the hopper 32. The hopper 32 then feeds a first pumping device 34 and a second pumping device 36, which are supplied by compressed air or other fluid, similar to the Guettler system. Granulate exiting the first pumping device 34 does so via the first hose 38 and then exits via the first nozzle 40. A further aspect of the Lightle method includes adding water at the first water inlet 42 just as the granulate is leaving the first nozzle 40. Similarly, granulate being pumped from the second pumping device 36 does so via the second hose 44 and second nozzle 46 whereat water is added at the second water inlet 48.
One problem with the Lightle unit is that once the truck bed 26 is devoid of granular material 28 (i.e. it""s empty), the truck 24 must depart the site to get refilled at some industrial location (that has the capability of filling a dump truck-sized bed). Since the hopper 32 is configured only to receive granulate from the truck bed 26, there is no other way for feeding the first and second pumping devices, 34 and 36 respectively. Also, the Lightle device does not include an on-board compressed air source (i.e. mounted to the vehicle itself). What is still needed, therefore, is a fully self-contained unitary vehicle that works for sand, gravel and equivalent granulates, that does not need to leave the site at any time to replenish the granulate.
In light of the aforementioned problems associated with the prior devices and methods, it is an object of the present invention to provide an Improved Apparatus and Method for Moving and Placing Granulate. It is an object that the present invention provide a portable, self-contained apparatus capable of discharging granulate into hard-to-reach areas, as well as providing assistance in covering vast open areas with granulate in a short time. It is a further object that the device and method permit the application of granulate into areas that are normally inaccessible and would require many hours of human labor, and thereby potentially avoiding damage to the site that might be incurred if employing a prior method and device. It is a still further object that the present invention serve to provide discharge of granulate near or adjacent to retaining walls and underneath concrete flatwork.